The field of cooking, baking, re-thermalizing and other heat-related food preparation has had very few substantial or revolutionary changes in the last several decades. Therefore and correspondingly, the cooking ware vessels that are used for heat-related food preparation have changed very little. Vessels of cooking which include, but are not limited to, pots, pans, skillets, sauce pans, woks, casserole dishes, kettles, or griddles tend to be made of metals or ceramics—both of which are opaque to most wavelengths of irradiation. The packages or cook-packs in which pre-packaged foods are sold are often made from materials which also are optically opaque or nearly so. Therefore, any irradiation that would be directed at the comestibles would be blocked from direct impact by the cooking vessel or packaging. With this arrangement, since the radiant energy hits the cooking vessel and does not directly hit the food item, direct heating by the irradiation is not possible, at least from those angles which block direct photonic impact into the food item. As the irradiation energy hits the cooking vessel or package it is either reflected or absorbed by it. The result is it heats up the pan, cooking vessel, or package instead of directly heating the food. In order to heat the food, a secondary thermal transfer must take place between the cooking vessel or package and the comestible target. This is an inefficient heat transfer process in most cases, and since much of the produced heat never touches the comestible, there is a large percentage of wasted energy.
Secondarily, when the heat does finally reach the food item it must be conducted from the outer layer to the inner layers of the food product. This inherently causes the outer surface of the comestible to reach a much higher temperature than the innermost areas of the product. It also slows down the cooking process since there is a maximum speed at which heat can be conductively and/or convectively transferred from the outer surface to the inner region of the food product without burning, drying, or overheating it.
Microwave cooking, which does not use traditional broadband heat, but rather bombards the food with radio frequency energy, cooks entirely differently. Most non-metallic materials are transmissive to radio frequency electro-magnetic energy. It heats by exciting or spinning free polar molecules which then create heat inside the food. It is not transmitting radiant photons or hot air to the food item. By contrast, any kind of direct radiant cooking process has associated with it the challenge of how to suspend or hold the food item in the direct path of the irradiation source to facilitate the cooking process.